In the secondary immune response, which immunoglobulin type increases rapidly?

In the secondary immune response, IgG is the immunoglobulin that increases rapidly. This response occurs upon re-exposure to an antigen after the initial infection or vaccination. During the primary immune response, IgM is typically produced first as part of the initial reaction. However, upon subsequent exposure to the same antigen, memory B cells that have been established during the primary response are activated. These cells quickly differentiate into plasma cells that produce IgG antibodies in large quantities.

IgG is the most abundant type of antibody in the bloodstream and is crucial for long-term immunity. Its ability to be produced quickly and to have a higher affinity for the antigen upon re-exposure is a key feature of the adaptive immune system's memory function. This enhanced response helps provide better protection against pathogens that the body has encountered previously.

While IgA, IgM, and IgE are important in various immune functions, they do not dominate the secondary response in the same way as IgG does. IgA is mainly involved in mucosal immunity, IgM is primarily produced during the initial response, and IgE plays a role in allergic responses and defense against parasitic infections. Thus, IgG's rapid increase is a hallmark of the secondary immune response, reflecting the efficiency of